超声空化在船舶与海洋工程中的应用

Biofouling on ships and offshore structures has always been a difficult problem to solve,which not only jeopardizes the structural strength but also brings great economic losses.Ultrasonic cavitation is expected to solve this problem due to its characteristics of no damage to structures and no pollution.Starting from the phenomenon and mechanism of ultrasonic cleaning,this paper introduces the application of ultrasonic cavitation in ship,pipeline and oil cleaning as well as ballast water treatment.By reviewing the existing studies,limitations such as insufficient ultrasonic parameter studies,lack of uniform cleanliness standards,and insufficient cavitation studies are summarized to provide traceable research ideas for improving ultrasonic cavitation technology and to guide the expansion and improvement of its applications.

To improve robustness of mechanical properties of semi-solid cast A356 alloy using taguchi design method

Mechanical properties of semi-solid casting are dependent on multiple processing parameters,and improper processing parameters will not only reduce mean data but also increase variations.The present study investigated the impact of parameters in slurry preparation and heat treatment on the yield strength and ductility of T6 heat-treated A356 Al-Si alloy using rapid slurry forming(RSF)semi-solid casting.The focus was primarily on the robustness of mechanical properties based on Taguchi design method.By analyzing signal-to-noise ratio and minimum value calculated from-3S,the optimum slurry preparation parameters and heat treatment parameters were determined to be no quench,enthalpy exchange material(EEM)temperature of 140℃,EEM-to-melt ratio of 6mass%,stirring time of 18 s,solution heat treated at 520℃ for 2 h,and ageing heat treated at 190℃ for 6 h.In a small batch validation,the-3S yield strength and-3S elongation reach 256.1 MPa and 5.03% respectively,showing a satisfactory robustness.The hardness and microstructure of heat-treated samples with the best and worst properties were characterized to gain insight into the underlying mechanisms affecting the mean value and variations of mechanical properties.

Vaccinia-related kinase 2 variants differentially affect breast cancer growth by regulating kinase activity

Genetic information is transcribed from genomic DNA to mRNA,which is then translated into threedimensional proteins.mRNAs can undergo various post-transcriptional modifications,including RNA editing that alters mRNA sequences,ultimately affecting protein function.In this study,RNA editing was identified at the 499th base(c.499)of human vaccinia-related kinase 2(VRK2).This RNA editing changes the amino acid in the catalytic domain of VRK2 from isoleucine(with adenine base)to valine(with guanine base).Isoleucine-containing VRK2 has higher kinase activity than the valine-containing VRK2,which leads to an increase in tumor cell proliferation.Earlier we reported that VRK2 directly interacts with dystrobrevin-binding protein(dysbindin)and results in reducing its stability.Herein,we demonstrate that isoleucine-containing VRK2 decreases the level of dysbindin than valinecontaining VRK2.Dysbindin interacts with cyclin D and thereby regulates its expression and function.The reduction in the level of dysbindin by isoleucine-containing VRK2 further enhances the cyclin D expression,resulting in increased tumor growth and reduction in survival rates.It has also been observed that in patient samples,VRK2 level was elevated in breast cancer tissue compared to normal breast tissue.Additionally,the isoleucine form of VRK2 exhibited a greater increase in breast cancer tissue.Therefore,it is concluded that VRK2,especially dependent on the 167th variant amino acid,can be one of the indexes of tumor progression and proliferation.

Photocatalytic application of magnesium spinel ferrite in wastewater remediation:A review

This review paper explores the efficacy of magnesium ferrite-based catalysts in photocatalytic degradation of organic contaminates(antibiotic and dyes).We report the influence of different doping strategies,synthesis methods,and composite materials on the degradation efficiency of these pollutants.Our analysis reveals the versatile and promising nature of magnesium ferrite-based catalysts,offering the valuable insights into their practical application for restoring the environment.Due to the smaller band gap and magnetic nature of magnesium ferrite,it holds the benefit of utilising the broader spectrum of light while also being recoverable.The in-depth analysis of magnesium ferrites'photocatalytic mechanism could lead to the development of cheap and reliable photocatalyst for the wastewater treatment.This concise review offers a thorough summary of the key advancements in this field,highlighting the pivotal role of the magnesium ferrite based photocatalysts in addressing the pressing global issue of organic pollutants in wastewater.

Key technologies of earthquake early warning system for China’s high-speed railway

Purpose–The purpose of this study is to introduce the top-level design ideas and the overall architecture of earthquake early-warning system for high speed railways in China,which is based on P-wave earthquake early-warning and multiple ways of rapid treatment.Design/methodology/approach–The paper describes the key technologies that are involved in the development of the system,such as P-wave identification and earthquake early-warning,multi-source seismic information fusion and earthquake emergency treatment technologies.The paper also presents the test results of the system,which show that it has complete functions and its major performance indicators meet the design requirements.Findings–The study demonstrates that the high speed railways earthquake early-warning system serves as an important technical tool for high speed railways to cope with the threat of earthquake to the operation safety.The key technical indicators of the system have excellent performance:The first report time of the P-wave is less than three seconds.From the first arrival of P-wave to the beginning of train braking,the total delay of onboard emergency treatment is 3.63 seconds under 95%probability.The average total delay for power failures triggered by substations is 3.3 seconds.Originality/value–The paper provides a valuable reference for the research and development of earthquake early-warning system for high speed railways in other countries and regions.It also contributes to the earthquake prevention and disaster reduction efforts.

Are we close to using Alzheimer blood biomarkers in clinical practice?

Alzheimer's disease(AD) is a progressive neurodegenerative disease histologically characterized by the presence of extraneuronal plaques,mainly formed by the 42-aminoacid isoform of amyloid-(Aβ_(1-42)),and by intraneuronal neurofibrillary to ngles,mainly formed by the tau protein and its hyperphosphorylated isoforms(p-tau).AD is the most common cause of dementia,with an estimated lifetime risk of about 1 in 10 for men and 1 in 5 for women.

Current observation and analysis based on mooring systems in the Andaman Sea

The basic structure and intraseasonal evolution of currents in the southeastern Andaman Sea was analyzed based on data collected in 2017 from two subsurface moorings(C1 and C5).Periodic variation in the upper ocean currents of the Andaman Sea was investigated by combining observational and satellite data.Mooring observations show that rapid changes of current speed and direction occurred in May and June,with a significant increase in current velocity at the C1 mooring.In the second half of the year,southward flow dominated at the C1 mooring,and alternating northward and southward flows were evident at the C5 mooring during the same period but the northward flow prevailed in boreal winter.In addition,analysis of the power spectra of the upper currents revealed that the tidal period at both moorings is primarily semidiurnal with weaker energy than that of the low-frequency currents.The upper ocean currents at the C1 and C5 moorings exhibited intraseasonal variation of 30-60 d and 120 d,while the zonal current at the C1 mooring exhibited a notable period of approximately 180 d.Further analysis indicated that the variability of currents in the Andaman Sea is influenced primarily by equatorial Kelvin waves and Rossby wave packets.Moreover,our results suggest that equatorial Kelvin waves from the eastern Indian Ocean entered the Andaman Sea in the form of Wyrtki Jets and propagated primarily along two distinct pathways during the observation period.In addition to coastal boundary Kelvin waves,it was found that a branch of the Wyrtki Jet that directly enters the Andaman Sea and flows northward along the slope of the continental shelf,and reflected Rossby wave packets by topography.

Synthesis and microwave absorption performance of heat-treated RF/SiO_(2)aerogels

The well-designed composite with satisfactory electromagnetic microwave absorption at high temperatures remains a serious challenge.Herein,we fabricated a resorcinol-formaldehyde/silica dioxide composite aerogel(RF/SiO_(2))with a three-dimensional network structure using sol-gel,atmospheric pressure drying technique as well as heat-treated processes to achieve enhanced microwave absorption capabilities in the low frequency range.The pristine RF/SiO_(2)aerogel presented a typical micropores structure with a surface area,porous volume,and density of 146.82 m^(2)/g,62.40%,and 0.28 cm^(3)/g,respectively.Remarkably,the RF/SiO_(2)aerogel showed an effective absorption bandwidth of 3.56 GHz and a minimum reflection loss value of-46.10 d B at 2.25 mm after being heat-treated at 1500°C,while the maximum effective absorption bandwidth was 3.60 GHz at 2.30 mm.The intricate three-dimensional networks possessed remarkable impedance matching,multiple attenuation mechanisms,interfacial polarization,and dielectric loss,which were attributed to the exceptional ability to absorb electromagnetic microwaves.It offered a fresh approach to creating adaptable and effective microwave absorption materials in military defense.

Exploring Deep Learning Methods for Computer Vision Applications across Multiple Sectors:Challenges and Future Trends

Computer vision(CV)was developed for computers and other systems to act or make recommendations based on visual inputs,such as digital photos,movies,and other media.Deep learning(DL)methods are more successful than other traditional machine learning(ML)methods inCV.DL techniques can produce state-of-the-art results for difficult CV problems like picture categorization,object detection,and face recognition.In this review,a structured discussion on the history,methods,and applications of DL methods to CV problems is presented.The sector-wise presentation of applications in this papermay be particularly useful for researchers in niche fields who have limited or introductory knowledge of DL methods and CV.This review will provide readers with context and examples of how these techniques can be applied to specific areas.A curated list of popular datasets and a brief description of them are also included for the benefit of readers.

Flexible capacitive pressure sensor based on interdigital electrodes with porous microneedle arrays for physiological signal monitoring

Flexible pressure sensors have many potential applications in the monitoring of physiological signals because of their good biocompatibil-ity and wearability.However,their relatively low sensitivity,linearity,and stability have hindered their large-scale commercial application.Herein,aflexible capacitive pressure sensor based on an interdigital electrode structure with two porous microneedle arrays(MNAs)is pro-posed.The porous substrate that constitutes the MNA is a mixed product of polydimethylsiloxane and NaHCO3.Due to its porous and interdigital structure,the maximum sensitivity(0.07 kPa-1)of a porous MNA-based pressure sensor was found to be seven times higher than that of an imporous MNA pressure sensor,and it was much greater than that of aflat pressure sensor without a porous MNA structure.Finite-element analysis showed that the interdigital MNA structure can greatly increase the strain and improve the sensitivity of the sen-sor.In addition,the porous MNA-based pressure sensor was found to have good stability over 1500 loading cycles as a result of its bilayer parylene-enhanced conductive electrode structure.Most importantly,it was found that the sensor could accurately monitor the motion of afinger,wrist joint,arm,face,abdomen,eye,and Adam’s apple.Furthermore,preliminary semantic recognition was achieved by monitoring the movement of the Adam’s apple.Finally,multiple pressure sensors were integrated into a 33 array to detect a spatial pressure distribu-×tion.Compared to the sensors reported in previous works,the interdigital electrode structure presented in this work improves sensitivity and stability by modifying the electrode layer rather than the dielectric layer.

Catalpa bignonioides extract improves exercise performance through regulation of growth and metabolism in skeletal muscles

Objective:To evaluate the effects of Catalpa bignonioides fruit extract on the promotion of muscle growth and muscular capacity in vitro and in vivo.Methods:Cell viability was measured using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay.Cell proliferation was assessed using a 5-bromo-2’-deoxyuridine(BrdU)assay kit.Western blot analysis was performed to determine the protein expressions of related factors.The effects of Catalpa bignonioides extract were investigated in mice using the treadmill exhaustion test and whole-limb grip strength assay.Chemical composition analysis was performed using high-performance liquid chromatography(HPLC).Results:Catalpa bignonioides extract increased the proliferation of C2C12 mouse myoblasts by activating the Akt/mTOR signaling pathway.It also induced metabolic changes,increasing the number of mitochondria and glucose metabolism by phosphorylating adenosine monophosphate-activated protein kinase.In an in vivo study,the extract-treated mice showed improved motor abilities,such as muscular endurance and grip strength.Additionally,HPLC analysis showed that vanillic acid may be the main component of the Catalpa bignonioides extract that enhanced muscle strength.Conclusions:Catalpa bignonioides improves exercise performance through regulation of growth and metabolism in skeletal muscles,suggesting its potential as an effective natural agent for improving muscular strength.

A perspective review on the biosynthesis of plant-based secondary metabolites and their application as potent drugs

Many phytochemicals and their derived metabolites produced by plants are extensively employed in commercial goods,pharmaceutical products as well as in the environmental and medicalfields.However,these secondary metabolites obtained from plants are in low amounts,and it is difficult to synthesize them at the industrial level.Despite these challenges,they may be utilized for a variety of medicinal products that are either available in the market or are being researched and tested.Secondary metabolites are complex compounds that exhibit chirality.Further,under controlled conditions with elicitors,desired secondary metabolites may be produced from plant cell cultures.This review emphasizes the various aspects of secondary metabolites including their types,synthesis,and applications as medicinal products.The article aims to promote the use of plant secondary metabolites in the management and treatment of various diseases.

Exploring the bioactive compounds of Feiduqing formula for the prevention and management of COVID-19 through network pharmacology and molecular docking

Background:To explore the effective chemical constituents of Feiduqing formula for prevention and treatment of coronavirus disease 2019(COVID-19).Methods:The compounds and action targets of twelve herbal medicines in Feiduqing formula were collected via Traditional Chinese Medicine Systems Pharmacology Database and Analytic Platform.The genes corresponding to the targets were queried through the UniProt database.The“herbal medicine-ingredient-target”network was established by Cytoscape software.The Gene Ontology function enrichment analysis and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis were performed by Database for Annotation,Visualization and Integrated Discovery.Molecular docking was used to analyze the binding force of core active compounds of Feiduqing formula with PTGS2,HSP90AA1,SARS-CoV-23CL hydrolase and angiotensin converting enzyme II(ACE2).Results:The“herbal medicine-ingredient-target”network included 434 nodes and 1948 edges,including 222 components such as quercetin,kaempferol,luteolin,etc.The key targets are PTGS2,HSP90AA1,PTGS1,ESR1,AR,NOS2,etc.Gene Ontology function enrichment analysis revealed 2530 items,including RNA polymerase II-specific,response to oxidative stress,transcription factor activity,etc.Kyoto Encyclopedia of Genes and Genomes pathway enrichment screened 169 signal pathways,including Human cytomegalovirus infection,Kaposi sarcoma-associated herpesvirus infection,Hepatitis B,Hepatitis C,IL-17,TNF,etc.The results of molecular docking showed that quercetin,luteolin,β-sitosterol,stigmasterol and other core active compounds have a certain degree of affinity with PTGS2,HSP90AA1,SARS-CoV-23CL hydrolase and ACE2.Conclusion:The active compounds of Feiduqing formula may have a therapeutic effect on COVID-19 pneumonia through the action on PTGS2,HSP90AA1,SARS-CoV-23CL hydrolase and ACE2,and regulating many signaling pathways.

Research progress on the main chemical constituents and pharmacological effects of Piper betle L.

The Piper betle,belonging to Piper genus of the Piperaceae family,is an evergreen and perennial creeper used in several traditional medicines.This plant has been known to possess antioxidant,antitumor,antibacterial,anti-inflammatory and antimalarial activities.A wide range of chemical compounds including alkaloids,simple phenylpropanoids,lignans,flavonoids,steroids,triterpenoids,sesquiterpenes,monoterpenes have been isolated from this plant.The present review summarized the information concerning phytochemistry and biological activity of P.betle,providing references for the future research of this plant.

Research progress on chemical constituents and pharmacological activities of Viburnum tinus L.

Viburnum tinus L.is a shrub native to the Mediterranean basin.Because of its sedative and antispasmodic activities,it is often used as a folk medicine in Europe.Phytochemical researches have shown that numerous chemical components,including iridoid glycosides,diterpenes,triterpenes,coumarin,flavonoids and anthocyanidins have been isolated from Viburnum tinus L..This study reviewed the chemical constituents and pharmacological activities of Viburnum tinus L.to provide a reference for further researches.

Research review on the main chemical constituents and pharmacological activities of Viburnum awabuki

Viburnum awabuki(V.awabuki),belonging to the Viburnum genus,is an ideal tree species for landscaping.Phytochemical investigations of the V.awabuki have resulted in the isolation and identification of coumarins,lignans,sesquiterpenes,diterpenes and triterpenes.It has been reported that the extracts of V.awabuki have multiple pharmacological activities,including anti-tumor,anti-oxidant,plant growth inhibitory and neurite outgrowth-promoting activities.The research progress on the chemical constituents of V.awabuki and pharmacological activities were summarized in this review.

A review of research on the main chemical constituents and pharmacological effects of Daphne odora Thunb

Plant of Daphne odora Thunb.has been used as medicinal plant since ancient times.In recent years,phytochemical studies have found that D.odora contains flavonoids,diflavonoids,coumarins,lignans,monoterpenes and other compounds,and shows extensive biological activities such as anti-inflammatory,immunomodulatory,neuroinhibition effects and so on.This article briefly reviews the recent research progress on the chemical constituents and pharmacological effects of D.odora at home and abroad.

Research progress on chemical constituents in Periploca forrestii and their pharmacological activities

Periploca forrestii Schltr.belonging to the family of Apocynaceae,is one of the“three treasures of Miao medicine”,which was utilized by the Miao people in China for the treatment of rheumatoid arthritis,fractures and wound.Phytochemical investigations have discovered that the main constituents of Periploca forrestii were steroids,terpenoids,flavonoids and their glycosides,flavanols,quinones and phenylpropanoids.Modern pharmacological studies have shown that it possesses a wide range of biological activities,such as anti-inflammatory,anti-rheumatoid arthritis,anticancer,immunosuppressive,neuroprotective and other properties.This paper summarized the primary chemical constituents and pharmacological effects of Periploca forrestii,hoping to provide a reference for its further development and utilization.

Research review on the main chemical constituents and pharmacological effects of Tripterygium hypoglaucum (Levl.) Hutch.

Tripterygium hypoglaucum(Levl.)Hutch.(THH),which belongs to Tripterygium genus of Celastraceae family,is widely used as the common Chinese herbal medicine.It has been reported that the chemical constituents of T.hypoglaucum include monoterpenoids,sesquiterpenoids,diterpenoids,triterpenoids,sesquiterpene alkaloids,flavonoids,anthraquinone derivatives,et al.These compounds showed a wide range of bioactivities,such as anti-inflammatory,anti-cancer,immunosuppressive,anti-HIV,anti-fertility and insecticidal activities.In this paper,we summarized the chemical constituents and pharmacological activities of T.hypoglaucum to provide a reference for its further research and developement.

Development of an Artificial Diet for Effective Oral Delivery of dsRNA to Soybean Pod Borer,Leguminivora glycinivorella(Lepidoptera:Tortrici-dae)

RNA interference(RNAi)technology is a promising crop protection strategy against agricultural pests.The soybean pod borer(SPB),Leguminivora glycinivorella(Mats.),is a serious pest of soybean in northeastern Asia.The neonate larvae of SPB are endophagous,initially feeding on the inner layer of the pod and then on the immature soybean seeds,a behavior that makes them difficult to rear.Therefore,a suitable artificial diet is desirable to facilitate RNAi research.Seven artificial diets and soybean pods were used for rearing SPB neonate larvae.The survival and mean weight of the larvae reared on artificial diet 6(A6,included 2 g soybean flour and 10 g R3 immature soybean pod powder)were found to be significantly higher than those for larvae reared on all other diets.Subsequently,A6 diet was prepared in DEPC-treated water to obtain a RNase-free artificial diet(RF).The survival and mean weight of the larvae were not significantly different between A6 and RF diets.Feeding neonate larvae with RF-SpbP0 dsRNA(ribosomal protein P0)silenced SpbP0 gene,resulting in arrested development and increased mortality.The results of this study suggested that the newly developed A6 or RF diets could rear SPB neonate larvae and help towards developing an effective method for oral delivery of dsRNA to SPB larvae.